Gas generator charged with solid combustible fuel



May 15, 1945. K; T. ALLEZ u 2,376,149

GAs GENERATOR CHARGED WITH soLID COMBUSTIBLE FUEL Filed May 26, 1 941 Patented May 15, 1945 l GAS GENERATOR oHARGEDvWIrHsoLID y COMBUSTIBLE-FUEL l Karl rlforsten Kalle,- Safl1e, Svveden r V Appl Inl charcoaL' or Woodech'arg'e'd fuel" gas v`generators "of 'the'types 'hitherto 'generally"employed l and based 'onithe 'reversed draught principle, the

' generatedfgas is 'c'zon'duct'ed'V through 'the layer of lcharcoallor"charcoaldust, i. fe?? the half burned orbroken upv pieces of'charcoal lying 'underneath the' combustion zone. 'Thei'disa'dvantage is hyerejbyinvolved that this layer of 'charcoal dust `is rendered' denser anddenserjso that in ja'comparatively short time it becomes impermeable tothe gas. It isthere'fore repeatedly necessaryto shut down the generator operation" inforder to yremove the lsla'gffrorn this agglomeratedYlayer Whichthen isl replacedby'larger pieces -ofresh charcoal coming from thelayerssituated thereabove.l

-In 'order .to 'eliminate-to a certain extent the disadvantage 'f these frequently 1 recurring and tiniewasting dees'lag'g'in'g operations it been sought in thel case-I` of Ycharco al 'charged Tgenerators to employ'. comparativelylarge pieces Lof 'charcoal of uniform 'size'and previously cleaned freefrom `dust"`an`d small'particles'vvhilst having as'hgh 'a strength as possible, 'so Vthat'the possibility 'has beenv realised to a certainjefitent "of 'avoiding the eroiisiii/ood; v c .v

Another disadvanta'gi'e e'nc'ountered with 'known types f,.'.g"as "generators ,"consists'infthe fact that 'the position `of `the ytwyer for 'pipe for the injectionV of' primary vair isl constant in relation to the commonly occurring doble 'conical constriction -f vth'ei'lre room and through which double thatlthe reductionv zone dueto its reduced compassvv can even j'shift out of the cone altogether. Ini'that event the riskA is encountered that prod'- 'ucts of ldryidistillvation f rolnthe lay'erofcljiarcoal lying 4vthereabeove vvvll together" with liberated Water' vapor due to' the vinherent moisture content of these charcoaUayers be *enabledrto' dodge past the reduction `zonejasl it jwere, Without 'entering into contactjvvith the red hot charcoal.

:It-is now'the purposejof thepres'ent'invention to eliminate the disadvantages above referred. to principally bythe v'provisionof a novel arrangement for the vremoval of vthe 'generated `gas from the gas "generator-and introducingf'combustion "air thereinto. More sp'ecicallythe invention relates tothe combination nja 'gas generatordesig'ned for engine propulsion and to be charged 'with solid c'ombustible'fueljof `gas'discharging means comprising atleast one gas'outlet Lpipe Lfor/the generatedv gas inserted in the 'fuel with combustionairjinjecting`means comprising at least one air jintakepipe'insertedin the fuelcharge, the

mouthslof said pip`es being 'positione'dfin relation to onefanother in a manner such as upon opera tion of the generator to cooperate -to'elimit'the extent ofthe'reaction'zones. l'

' It has turned out that with'` an arrangement working on' this principle the possibility is afforded 'of providing' an advantageous` mutual disposi-y tion vand lilfnitedextent of the oxidation andf reduction' zonesrrespectively Whilstat the same time achieving by simple! means a'favourable adaptability orfr'esponse on thepart of thegeneratorto cone'ithe 'gases are fforced- 'ii-downwards. The f mouth of the .air injecti'grneans Ais" t1fie'ngener ally'so situated that up'onoper'a'ting the generator tothe/full extent of itsfvvorkin'g capacity the miidatimfik zone win'startito shiftdown in the direction towards the mouth; of the cone with "the result thatthe'reduction zoneithen oc'cupies'the whole of the 'cone jitis "at thisjuncture that' thegenerator is 'functioning 'at'its' best. Onfair'- lylow or very low loads, say for example when in automobile engine'suppiied'fby 'the generator is idling, the oxidation Zone dueto 'the' V small quantitylj of injected 'airQslipp'ly"Will lshift 'furth'e'r up-y Wards to a considerable extent with Vthe Vresult By the disposition of aspecial dischargepipe (orvajplural'ity of such pipes) rinsertedint'o .the Woojd or charcoal charge respectively the advantage is further achieved that the conducting otr gas fromout of the receptacleiis renderedindependentofA vthe density ofrpacking of thev morefor lessv incinerated flayers of charcoal e underneath which thegas rin the case of the earlier typesl of generators "referred to abovehas to pass. ,This in itsgturn brings with it less dependenceof the qual-y ity of the fuel.

According to a preferred embodiment) of the invention the gas discharge pipey or pipes respectively are arranged concentrically .around such as charcoal particles tending to choke up the opening of the gas discharge pipe.

In combination with the gas discharge pipe (or pipes respectively) at its end opening out into the mass of charcoal or wood inlet openings can be formed which are so adapted as to permit the passage of gas, but to obstruct the entry of the charcoal particles into the gas discharge pipe. The said openings are preferably made so ne that at this point charcoal dust and other impurities are already removed to a considerable extent from the gas. The said inlet openings can present the form of slits in the wall of the gas discharge pipe, whereby a grating is thus formed and in this case the lgas outlet pipeis preferably arranged to be movable in an outer xed pipe serving as a guide therefor and presenting scraping means co-operating with the said grating. Alternatively the inlet openings can be constituted by slits of the kind described formed in the wall of a relatively small fixed pipe piece connected to the air injecting pipe at the lower end thereof and also forming a grating which concentrically and with some intermediate play surrounds the said pipe and enters the lower end of the gas discharge pipe, which in this case may be fixed. In both these cases the grating can appropriately be be kept moving during operation of the generator so that charcoal dust, carbon particles etc. easily are removed at the slits.

This grating device according to the invention renders it possible to employ charcoal containing a comparatively large quantity of dust and small particles, whilst aiording the facility of thereby attaining a higher temperature in the oxidation .pipe (that is to say in the case when the grating is formed therein) can bemade automatically movable during the generator operation in such a manner that the possibility is alforded of the oxidation and reduction zones respectively becoming increased or reduced in extent according to .the fluctuating gas demand. By means of this arrangement it is also made possible to satisfy the condition that the inlet openings, i. e., the grating slits for the gas discharge pipe will always be located in the region of the reduction zone so that the gas will be forced in its entirety inslol pass through this zone before proceeding fur- The automatic movement of the air injecting pipe and also of the gas discharge pipe-can according to the invention be obtained by the Variable vacuum in the gas discharge pipe varying with the iiuctuating gas consumption, whereby this vacuum is enabled for example to act on a bellows or diaphragm d vice xed to the air injecting pipe or the gas ischarge pipe respective- Further features of the invention will `be evident from the following description of three embodiments of the device for gas generators respectively, represented in the accompanying drawings by way of example:

Figure l represents the iirst of these embodiments, and Fig. 2 the second whilst Figs. `3 and 4 show on a somewhat larger scale the lower end of the gas discharge pipe with the grating according to Fig. 2 in cross-sectional elevation and horizontal section respectively. Fig. 5 represents in a manner similar to that according to Fig. 3 the third embodiment.

Referring to Fig. 1 a pipe or twyer I for the injection of primary air is arranged in the fuel receptacle 4 charged with solid combustible fuel, such as charcoal or wood, the said air entering at'the upper end 6 of the twyer. 'A discharge pipe 2 opens out at or in the vicinity of the oxidation and reduction zones 5 and the generated gas is conducted away from the receptacle therethrough. In the case represented this discharge pipe 2 is arranged concentrically around the air injecting pipe I, the end of which extends a little beyond the end of the pipe 2. The generated gas is thus conducted between the two pipes I and 2 and departs through an outlet pipe 3 branching out from the pipe 2. The distance between the respective lower ends of the pipes I and 2 is adaptable according to the relative situation and the extent of the reduction and oxidising rones respectively. The air injecting pipe I can according to the invention be arranged to be movable relatively to the discharge pipe 2, so that it can be shifted up and down and thus also serve as a cleansing device in the event of charcoal particles or other impurities choking up the lower end of the discharge pipe 2. To this end the injection pipe I is appropriately provided with a handle at its outer end.

It will be seen with reference to Fig. 2 that the injecting pipe I and the gas discharge pipe 2 are likewise relatively movable in their longitudinal direction and are located in a surrounding pipe 1 fixed at 8 to the receptacle 4 and serving as a means for guiding the inner pipes. The generated gas is taken roff through a pipe 9 branching from the surrounding pipe 1.

At the lower end the gas discharge pipe 2 is provided with Aa grating I1 formed by slits in the wall, see Figs. 3 ande, through which the generated gas is introduced. At its lower end the outer pipe 1 surrounds the grating Il so that a larger or smaller part of the grating opening will be exposed. The injecting pipe I is passing the bottom of the grating pipe 2 through an opening I8 and thereby a guidance for the same is obtained.

The slits ofthe grating I'I through which the gas is sucked into the pipes 2 and 'I from the reduction zone formed by the surrounding layer of charcoal are 'relatively narrow, varying from 0.1-3 millimetres according to the different design and purpose involved, and it is of course desirable that the slits shall be as fine as possible. The said slits serve namely as lters for charcoal dust, through which only the finest particles are allowed to penetrate into the grating pipe 2 so as then to pass through the pipe 9. In this way the gas undergoes preliminary cleaning to a considerable extent.

Bellows or diaphragme indicated by I0 and Il are fixed to the grating pipe 2 and the injecting pipe I at points l2 and I3 thereon respectively. I4 and I5 refer to spiral springs which tend to become elongated and thereby exercise a displacing action on the air injecting pipe I and the grating pipe 2 respectively in the direction of the arrow I6.

The mode of operation of the above-described arrangement is as follows:

When gas is sucked out through the pipe Il for example by an automobile engine connected asma-14% action:x of lthel spiral :springsrlll .andf- I l.; It will be evdentzathat theiwgreater ais thelsuctionflset -up iin .thel pipeal, 1in other Wordspthe. more rapidly' the? engine -Iis runninf-n.l the. .greaterfwill lzbehthe aduana.-

tity of gas requiredf therebyand correspondingly.i'` increasedcwill :be: thez'extent'. ofethe: vacuum effect exercisedspns#theydiaphragmsuwhich .'vacuunrris practicallyJ speakinguequaltto the amount) of vac f1; uunra: createdffinather. l actual z-generator. .recepta-'rl clem. fv. r

Whencthe vacuumincreases the-'grating pipevz` i will',obes.pushed .further :downs into :,the .charcoal layerfinztheagenerator. i* This means. not :only that a largercportion; of i' the igrating will: be left 'exe,l .20Il posedgci sos .thataa i largercquantity:icf.gas:iis zen-s abledrito .ow-allzthezimore-geasily- :into ..theizpipe 2,

but.-a1so:;that-.: the injectingzpipe; -I is pressedz-fun..

therfdown'f; that is to=say to 'such arr-.extent thats.

i The pressure letect thu'siexercised 1'one 5 i; thezidiaphragmsecanfbe counterbalancedaby's.the:.I

through-.thel-reduction :zone possibly; thexoxlw idising zone Arespectivelys Thisf consideraticnqis,ll .-1 aboveaall, 1 `of f great importancel in those.;y cases, where the charcoal is mixed with wateraor it contains :piecesof funcarbonized-wood.;v

Thex embodiment according to Fig: 5 canlbeisaid to lconstitute La combination of theV .two .embodia f ments just described; Allt tha-'tis retained. in-.this. caser of s the piper 2 according lto :Figs` 2-4, .is the .f

'lower end ipiece provided with :thel gratinggopen-A ings ;l`Iz-andf,this;end lpieceatithe point IB is xed to. :.theazinjecting ipipe .l and thusparticipatesy in theizmoyementl thereof.= Between 'the' Vfixed -pipel y. l, which: in this case accordingly 1 serves asathe a dia'phragmiacted upon byther vacuum .in then.: pipegz'lv and-.effectingautomatic-movement of the@ ppecll mayzbe 'interposed analogously 'to fthe.' case represented-in1Fig: 2.

Y Itiwilliof courselbe,appreciated that theme-th.-v od. 7hereiribefore describedot effectingthefauto- 'matic moivementnofwthe -injectingapipei andtheA f gas.discharge.pipes-respectively; whilst employing theizvarying sucticnze-iectrin the outlet pipe trom theidistancel-.from its endqopeninguto kthe grating=f25rgthevgeneratorg or i the .variationin the --vacuum is .madeylargert Tha fpurposefof f this.. is vthatz'with the;- larger e quantitygof airfwhich eanibeintroclucedgand with..y the larger quantity of gas respectively;-which;

can departcthroughgthe enlarged grating open- 30g-i,-

ing, the oxidation and the reduction Zones respectively will thus be caused to increase in size, which increase is effected by the automatic prolongation of the injecting pipe I. The zones in question are represented in Fig. 1 by the refer- 35 ence 5.

' Due to the fact that the injecting pipe I is movable the freely extending endof the grating pipe 2 can for different rates .of air-flow always be kept red-hot at round about 800 C; This 4.o

K count.

The upward and downward displacement of the grating pipe 2 also constitutes an assurance that charcoal particles possibly fixed to' the grating will be' removed, so that-the grating is constantly kept automatically clean and open.

Since in the case represented the oxidation zone is situated, as it were, underneath the reduction zone, i. e. contrary to what is usually the case, dust formation can never take place, nor can agglomerates of clogged ordinary and charcoal dust accumulate in the actual reduction j zone because the downwardly falling and scraped oi charcoal particles always have to pass the reduction zone before entering the oXidising zone and there becoming burned up. It is evident that in this way scraping out of slag, such as is necessary in-the case of ordinary gas generators of known type is in the present instance'superlfluous, inasmuch as practically everything is effectively burned up.

Due to the fact that the grating I 'I is displaceable relatively to the surrounding pipe 1, the reduction zone will always completely cover the supply inlet for the generated gas in the grating, sothat moisture vapors or products of dry distillation from the layer of charcoal above cannot depart through the grating without first passing produced gzthereby; can-'be xdesigned'yto ftakei place inlafmannerfother than thathe're represented.

Inlc theipevent 4of ztheir :generatori being employed in .association with. an automobile engi-ne'for ex-y ampleg.f fit; is ipossiblesto f utilise the: varying vacuum occurringabetweenathe Carburettor throttle fand the engine proper to effect the desired movement of air injecting pipe I and gas discharge pipe 2 respectively, which vacuum bears a certain relationship to the engine speed and the quantity of gas sucked in respectively.

In the embodiment according to Figs. 2-4, wherein both pipes are represented as being movable, the automatic displacement of the injecting pipe or pipes respectively can be elected by thevacuum'uctuations in the generator fuel receptacle and the displacement of the gas discharge pipe or pipes respectively by the vacuum occurring between the Carburettor throttle and the engine proper, or vice-versa.

I claim:

1. -In a gas generator designed for engine propulsion. and comprising a receptacle for solid I. combustible fuel, the combination ofan assembly of means extending downwardly into said receptacle and fixed thereto, comprising at least one outlet discharge pipe for the generated gas, and means comprising at least one inlet pipe surrounded by the outlet discharge pipe, the lower end of the inlet pipe projecting further into the receptacle than the lower end of the gas discharge pipe.

2. In a gas generator of the kind claimed in Y claim l, the inlet pipe and discharge pipe being relatively movable axially whereby the distancev between their lower ends may be adjusted and the inlet pipe may be employed to prevent choking of the lower end of the discharge pipe.

3. A gas generator as claimed in claim 1 in which the lower end of the discharge pipe is completely sealed and the wall of the discharge pipe at its lower end portion is provided with intake openings of a neness permeable to the gas generated, but obstructing the entry of charcoal particles and thelike. i

4. A gas generator as claimed in claim 1 in which the gasdischarge pipe has its lower end completely sealedr and saidpipe is provided near its lower end with peripherally disposed slits forming a grating, and auxiliary guiding andv scraping means cooperating with said grating to free the latter from clogging charcoal deposits and the like.

5. -In a gas generator designed for engine propulsion and comprising a receptacle for solid combustible fuel, the combination of an outer gas discharge pipe extending downwardly into said receptacle and fixed thereto, a movably mounted inlet pipe surrounded and guided by said gas discharge pipe, said inlet pipe `also extending into the receptacle beyond the lower end of the gas discharge pipe and provided at its lower end portion with a peripherally disposed gas filter grating which is fixed thereto and arranged above its lower end, said grating being movable in sliding relation with the end of the gas discharge pipe.

6. In a gas generator designed for engine propulsion and provided with a receptacle for solid combustible fuel, the combination of an outer tube extending downwardly into the receptacle and xed thereto, an axially movable outlet pipe for the generated gas surrounded and guided by said outer tube, and a movable inlet pipe surrounded by said outlet discharge pipe, the lower end of the inlet pipe projecting further into the receptacle than the lower end of the gas -discharge pipe, the latter being provided with peripherally disposed slits forming a grating arranged to move in substantially sliding relation with the end of the guiding tube so as to be scraped free of clogging charcoal dust, carbon particles, and like deposits.

7. A gas generator as claimed in claim 6 including means responsive to the pressure existing in the receptacle for moving the gas discharge pipe relatively to the tube to effect such scraping.

8. A gas generator as claimed in claim 6 including means responsive to pressure Within the receptacle for moving .the inlet pipe relatively to the outlet pipe, and for moving the outlet pipe axially relatively to the outer tube.

9. In a gas generator designed for engine propulsion and comprising a receptacle for solid combustible fuel, the combination of an outer -gas discharge pipe extending downwardly into said receptacle and fixed thereto, and a movably mounted inlet pipe surrounded and guided by said gas discharge pipe, said inlet pipe also extending into the receptacle beyond the gas discharge pipe and provided at its lower end portion with a peripherally disposed gas filter grating which is xed thereto and arranged above its lower end to move in substantially sliding relation with the lower end of the gas discharge pipe, and means for causing axial movement of the inlet pipe dependent on a pressure fluctuating within the receptacle, said means comprising a diaphragm secured to the inlet and discharge pipe.

KARL TORSTEN KLLE. 

